Cerebrovascular imaging in vivo by non-contact photoacoustic microscopy based on photoacoustic remote sensing with a laser diode for interrogation

Photoacoustic microscopy (PAM) is a unique tool for biomedical applications because it can visualize optical absorption contrast in vivo. Recently, non-contact PAM based on non-interferometric photoacoustic remote sensing (PARS), termed PARS microscopy, has shown promise for selected imaging applications. Avariety of superluminescent diodes (SLDs) have been employed in the PARS microscopy system as the interrogation light source. Here, we investigate the use of a low-cost laser diode (LD) as the interrogation light source in PARS microscopy, termed PARS-LD. A side-by-side comparison of PARS-LD and a PARS microscopy system using an SLD was conducted that showed comparable performance in terms of resolution and signal-to-noise ratio. More importantly, for the first time to our knowledge, in vivo PAMimaging of mouse brain vesselswas conducted in a non-contact manner, and the results show that PARS-LD provides great performance. (C) 2021 Optica Publishing Group

Automated summary

Photoacoustic microscopy (PAM) is a valuable tool for visualizing optical absorption contrast in vivo. In this study, a low-cost laser diode (LD) was used as the interrogation light source in a non-contact PAM system called PARS-LD. The performance of PARS-LD was comparable to a traditional system using a superluminescent diode (SLD), and in vivo imaging of mouse brain vessels was successfully demonstrated.